This provides a shorthand for specifying the reader,
writer,
or accessor names.
If the attribute is read-only ('ro') then it will have a reader method with the same attribute as the name.

If it is read-write ('rw') then it will have an accessor method with the same name.
If you provide an explicit writer for a read-write attribute,
then you will have a reader with the same name as the attribute,
and a writer with the name you provided.

Use 'bare' when you are deliberately not installing any methods (accessor,
reader,
etc.) associated with this attribute; otherwise,
Moose will issue a deprecation warning when this attribute is added to a metaclass.

Returns the subroutine reference of a method suitable for reading or writing the attribute's value in the associated class. These methods always return a subroutine reference, regardless of whether or not the attribute is read- or write-only.